F215 - Revision thread 13th June 2011

It was going okay, till about 4minutes ago...I stumbled across the thread about Sarfaraz Shah being shot dead by police officers.. and the video has made me feel so shocked/sick I'm put off revision. Some people are so heartless it makes me really sad

I hope it's going well for you?

Conservation Vs Preservation?

Module 1 is quite big as is Module 2...so we can expect q uite a few questions

But Module 3 and 4 are much shorter and it is quite easy to see which topics have and have not been examined yet

Would'nt you expect Sequencing PCR to come up? There was a 9 mark question on DNA replication? in F212 hmm

Yeah, it's pretty disgusting how they can just kill a person like that - too much corruption.

Haha, mines okay - but I haven't been doing that much for this anymore, since it'd just be me going over it again, gonna condense my notes today so will see

Conservation is the maintenance of biodiversity, it involves maintaing a habitat that has been destroyed, or is on the verge of destruction - it involves reclaiming the habitat as well.

Preservation - is preserving a habitat in it's untouched form, it differs from conservation as it's not trying to improve biodiversity, just maintain it.

I'm sure PCR was in the Jan 2011 paper?
maybe electrophoresis, plasmids, vectors, genetic markers..

bit of maths :P

I'm sure PCR was in the Jan 2011 paper?
maybe electrophoresis, plasmids, vectors, genetic markers..

Oh that's really good You seem to be doing really well!!
and yes stupid Zardari

cAMP - its role in modifying 3d protein structure

The sliding filament model controls muscle contraction. When a muscle is not contracting a molecule onf tropomyosin covers the binding site for the myosin head group on actin, and is held in place by troponin. When an action potential arrives, calcium ions are released into the sarcoplasmic reticulum and bind to troponin molecules. The shape of troponin changes and tropomyosin moves away from the binding site on actin.

The myosin head attaches to the actin filaments- a cross bridge is formed.
The myosin head bends and pulls the thin (actin filament) over teh thick myosin filament. This is called the POWER STROKE>
ADP and Pi are released.

The cross bridge is then broken and ATP attaches to the myosin head.
The head moves backwards as the ATP is hydrolysed to ADP and Pi and can form a cross bridge with a thin filament further along.

How is teh ATP supply maintained?
Aerobic respiration in muscle cell mitochondria produces ATP providing there is enough oxygen and respiratory substrate.
Anaerobic respiration in muscle cell sarcoplasm (leads to roduction of lactic acid which is toxic- released into blood and redirects blood to muscles)
Transfer of phosphate group from creatine phosphate in muscle cell sarcoplasm to ADP to form ATP. Catalysed by creatine phosphotransferase.

basically, cAMP is a second messenger - when the hormone binds to the receptor on the target cell, adenyl cyclase converts ATP to cyclic AMP which is able to activate proteins by altering there 3d shape, or activating enzymes to do the work.

there was a question to compare pcr with something else. they didn't tell us to outline pcr

What do we actually need to know for artificial selection of bread wheat?
I've just got take wheat plants with high wheat yield, get highest yield offspinr breed them together, continue over several generations etc. . .
Do we need to know Figure in the OCR book with all the different chromosome numbers? :/

Ohh okay. thank you!
Succession........ ?

Hate maths

I've just learnt the example in the CGP guide tbh, I wouldn't expect them to make us remember all that polypolidy and selection stuff, doesn't make sense considering you didn't have to with animals either. They could ask how the hybrid is sterile maybe, which the answer would be because of no homologus pairs of chrosomes, so gametes produced with the wrong number etcetc

You and me both .. I originally took further maths and was like ..

is the directional change in a community over time, occurs in seral stages and starts of with a pioneer species which is able to colonize the land and produce an organic soil when it dies and is decomposed. this makes a soil for which larger plants can grow, this continues until a climax community is reached, where the community of organisms are at there maximum.

i love using rocks as an example :P
1) mosses and lichens grow on rock, eroding it - providing minerals, they die and decompose etcetc soil blahblah tolerate conditions blahblah
2) allows for larger plants like ferns to grow on the soil
3) blahblah continues until trees occupy the last seral stage, so climax community reached.

Yeh, just a description of an embryo. We need to know some key differences between somatic gene cell therapy and germline gene cell therapy. Changes to germline cells in germline cell therapy ccan be passed onto offspring, wheras in somatic cell therapy changes to the genome are restricted to the actual patient. In germline cell therapy it is easier to insert the allele in its functioning state into the germline cells, however their are ethical issues about altering the human embryo. With somatic cell therapy, it is more difficult to insert the allele into the and target cells e.g techniques which are difficult must be used e.g. ex vivo. With somatic cell therapy, it may need to be repeated regularly because treatment is short-lived, wheras germline cell gene therapy is permenant modification to the germline. All cells derived from germline gene cell therapy contain a functioning copy of the allele. With somatic cell gene therapy it is difficult to insert the allele in its functioning state- use of genetically modified viruses and liposomes. Inserting an allele into an embryo in germline gene cell therapy is easire but may cause uintentional changes. It is considered unethical to engineer human embryos.

Great!

Galapagos Islands?